Transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles

Polymer brush-grafted nanoparticles have significant application value in fields such as gene therapy and targeted drug delivery. A profound understanding of the interaction mechanisms between these particles and cell membranes represents a critical scientific challenge in biophysics. Using the self-consistent field theory (SCFT), this work systematically explores the transmembrane transport of polymer brush-grafted nanoparticles into giant vesicles. The impacts of critical parameters — polymer brush grafting density, nanoparticle size, and giant vesicle membrane thickness — on transport behavior are comprehensively elucidated. The findings reveal two distinct transmembrane transport mechanisms for polymer brush-grafted nanoparticles, which are governed by membrane thickness and grafting density. At high grafting density, the nanoparticles undergo direct transmembrane translocation; at low grafting density, transport occurs via endocytosis. Thermodynamic analysis identifies entropy as the dominant driving force for this process.